R/tam_pv_mcmc_calc_probs_irf_3pl.R

In alexanderrobitzsch/TAM: Test Analysis Modules

## File Name: tam_pv_mcmc_calc_probs_irf_3pl.R
## File Version: 0.32


tam_pv_mcmc_calc_probs_irf_3pl <- function(theta, AXsi, B, guess,
        subtract_max=FALSE, resp.ind )
{
    if ( is.vector(theta) ){
        theta <- matrix( theta, ncol=1 )
    }
    nnodes <- nrow(theta)
    nitems <- nrow(AXsi)
    maxK <- ncol(AXsi)
    if ( is.null(guess) ){
        guess <- rep(0,nitems)
    }

    #--- compute probabilities
    I <- nitems
    res <- tam_rcpp_pv_mcmc_calc_probs_irf_3pl(theta=theta, B=as.vector(B), I=I, maxK=maxK,
                resp_ind=resp.ind, AXsi=AXsi )
    rprobs <- array( res$rprobs, dim=c(I,maxK, nnodes) )

    # include guessing
    rprobs0 <- rprobs
    ind <- which(guess > 1E-6 )
    if ( length(ind) > 0 ){
        rprobs[ ind, 2, ] <- guess[ind] + ( 1-guess[ind] ) * rprobs0[ind,2,]
        # include guessing here
        rprobs[ ind, 1, ] <- 1 - rprobs[ ind, 2, ]
    }
    probs <- rprobs
    probs <- aperm( probs, c(3,1,2) )

    #--- OUTPUT
    return(probs)
}